4L60E Information Thread (Includes 4L65/70/75)

[NickTransmissions]

Bumping this thread up with a new video on measuring servo travel/adjusting band clearance in 700R4s and 4L60Es....This vid is one of a two-part series and focuses on GM factory servo and hardware. PT2 will focus on aftermarket servo set ups (Coming soon).

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[NickTransmissions]

Bumping this thread with a new video on 700R4 and 4L60E Forward Drum Repair...The most common pattern failure, by far, is the 3-4 clutch pack burning up...The primary reason for this in my view, is leaks developing at the base of the input shaft where it's pressed into the drum...Over time, milage, stresses and other factors combine to weaken the drum to the point it's no longer making a perfect seal at the 2-3 feed circuit and fluid begins to leak into the case under high pressures when it should be going directly to the 3rd clutch piston to apply and hold the 3-4 clutch pack...When this starts happening, 3-4 clutch failure isn't far behind.

I show a potential repair procedure using Loctite retaining compound, that if ultimately proves itself to work under operating temperatures, will be a viable option for those looking to repair drum assemblies with mild to moderate leaking in lieu of replacing the drum.

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[Vbb199]

Nick i have a question for you, relative to 4L60e stuff for anyone here. I build automatics myself, mostly 3 sp and 4 sp. not for a living but for myself and friends, from stock to higher hp.

Whats your goto method for deleting the PWM function of the tcc solenoid?

Some install the transgo SK-4L60E with the bigger valve
Some pin the valve with 700r4 spring or two check balls
Some remove the outer O ring and file/grind a notch straight to the filter.


What do you do? And whats the consequences of one vs the other?

 

[NickTransmissions]

Nick i have a question for you, relative to 4L60e stuff for anyone here. I build automatics myself, mostly 3 sp and 4 sp. not for a living but for myself and friends, from stock to higher hp.

Whats your goto method for deleting the PWM function of the tcc solenoid?

Some install the transgo SK-4L60E with the bigger valve
Some pin the valve with 700r4 spring or two check balls
Some remove the outer O ring and file/grind a notch straight to the filter.


What do you do? And whats the consequences of one vs the other?

Those will all work but I like the Fitzall valve as it completely seals the bore and is appx $25.00. The others convert the PWM to On-off as well and ill use those methods if the bore is otherwise fine when vac tested.

 

[Vbb199]

Those will all work but I like the Fitzall valve as it completely seals the bore and is appx $25.00. The others convert the PWM to On-off as well and ill use those methods if the bore is otherwise fine when vac tested.

How do you feel about the big pressure spike? Ive heard things about it allegedly tearing up converter bushings and this and that but i havent seen any evidence of it myself. Im speaking more so when the PCM/TCM on/off pressure tables have been modified to match what you physically want the converter to do if that makes sense.
Most stock management has the converter slipping in and out, and it can be changed for full lock/unlock with no slip, but you can still see some slip on a monitor/laptop until you fully lock the valve out.

Does the pressure become dangerous to anything with a blockoff/pin + PCM modification